Develop Reference

Connecting Android Phone to local host

In my application i am using API's which are hosted on local server, and can be accessed on network. On emulator it works fine as it is connected to proper network. When I am using app on my phone it wont.
Is it possible to access local API's through phone with our normal internet connection?
I am using below http code for accessing API's.
public String getResponse(String url, int method, String postParameter) {
HttpResponse response = null;
// Creating HTTP client
HttpClient httpClient = new DefaultHttpClient();
// Creating HTTP Post
HttpPost httpPost = new HttpPost(url);
// Building post parameters
// key and value pair
List<NameValuePair> nameValuePair = new ArrayList<NameValuePair>(2);
nameValuePair.add(new BasicNameValuePair("jObj", postParameter));
// Url Encoding the POST parameters
try {
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePair));
} catch (UnsupportedEncodingException e) {
// writing error to Log
e.printStackTrace();
}
// Making HTTP Request
try {
response = httpClient.execute(httpPost);
// writing response to log
Log.d("Http Response:", response.toString());
} catch (ClientProtocolException e) {
// writing exception to log
e.printStackTrace();
} catch (IOException e) {
// writing exception to log
e.printStackTrace();
} catch (Exception e2) {
e2.printStackTrace();
}
return response.toString();
}
Is there any setting which we can do for accessing through our normal internet?
Thanks in Advance

If you have it hosted on your local machine, you will have to find a way to connect both your phone and your local machine on the same network (most commonly Wifi). A simple work-around to this is creating a hotspot in your android device and connecting your local machine to it. Make sure to set the correct IP address in the android app.

Find your local machine ip address where the api's are hosted
using ipconfig and pass on the ip address in url
your url should be like 192.168.0.102 which is assigned by modem.

Answering as I cant comment, Please check that your phone is connected to your network and not using mobile data or some other WIFI network outside of your network.

Android authentication using JSON

I have a Python/Django server that is the API for a web service.
I'm building an Android application that will communicate with the API and authenticate users, and enable them do all pulls/pushes from the server.
My trouble is with the particular communication with the server. Currently I use my WiFi network, and run the server like so python manage.py runserver 192.168.1.3:8000 so that it is available to any test device on my LAN.
The API is written so it returns http status messages with every response, so that I can tell the success or failure of a request before parsing the JSON reply.
On my Android side, I have used HttpURLConnection because it has the getHeaderField(null) method that I use to pick the http status message from the response. I get a status message 200 [success] when I 'ping' my server - this is a sort-of proof of concept.
My real issue is authentication. My API requires I send it a JSON with data, and it returns a JSON response [with an http status message in the head].
I can't seem to figure out how to do this. The JSON action I've seen around the interwebs are merely picking, or posting.
I am wondering how I can POST and pick up a response from the server.
Extra information
- Server supports HEAD and GET and OPTIONS.
- Assuming server home is 192.168.1.3, user login/register would be in 192.168.1.3/user, events would be in 192.168.1.3/events and so on..
- This was the closest I got to figuring out a solution, but not quite..
CODE from the AsyncTask
protected JSONObject doInBackground(String... params) {
publishProgress(true);
/*Create a new HttpClient and Post Header*/
JSONObject result=null;
HttpClient httpclient = new DefaultHttpClient();
try {
URL url = new URL(cons.PROTOCOL,cons.SERVER,cons.PORT,"/user");
HttpPost httppost = new HttpPost(url.toURI());
HttpResponse response =null;
/*Add your data*/
JSONObject j1=new JSONObject();
JSONObject json=new JSONObject();
j1.put("username", "test");
j1.put("email","test#test.com");
j1.put("password","password");
j1.put("first_name","John");
j1.put("last_name","Doe");
json.put("user",j1);
json.put("mobile_number","256774622240");
StringEntity se = new StringEntity( json.toString());
se.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
httppost.setEntity(se);
/*Execute HTTP Post Request*/
response= httpclient.execute(httppost);
Log.i("jazz","It's ALIVE!!!!!");
Log.i("jazz",response.getStatusLine().toString());
} catch (ClientProtocolException e) {
/* TODO Auto-generated catch block*/
} catch (IOException e) {
// TODO Auto-generated catch block
} catch (URISyntaxException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return result;
}

If your are building your HttpPostRequest well, and you only want to know how to attach JSON, here you are a possible solution for it:
StringEntity formEntity = new StringEntity(yourJsonObject.toString());
yourPostRequest.setEntity(formEntity);
I hope this helps!
PS:In addition, let me recommend you the use of this component:
https://github.com/matessoftwaresolutions/AndroidHttpRestService
I've used it in an Android app that is connecting to a python server API and it makes http request easier for your Android client.

Okay, so I'm now answering my own question :D
The issue was with the path variable in the URL string.
This is the format of one of the URL constructors based on this document.
URL(String protocol, String host, int port, String file)
Since I am posting the JSON to the /user path, that's the one I insert into the constructor as the directory.
So, my URL was formed like so:
URL url= new URL("http",cons.SERVER,cons.PORT,"/user/");
My mistake in the beginning was using /user instead of /user/
but other than that, the URL structure and connections are all alright.

How to implement post method for this http post request ?

Hi this is my HTTP Post Request Method in Android client.i don't know how to implement the #POST method in the Restful web server.
public class AndroidHTTPRequestsActivity extends Activity
{
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Creating HTTP client
HttpClient httpClient = new DefaultHttpClient();
// Creating HTTP Post
HttpPost httpPost = new HttpPost(
"http://localhost:8080/GPS_Taxi_Tracker_Web_Server/resources/rest.android.taxi.androidclientlocation/Login");
// Building post parameters
// key and value pair
List<NameValuePair> nameValuePair = new ArrayList<NameValuePair>(2);
nameValuePair.add(new BasicNameValuePair("email", "user#gmail.com"));
nameValuePair.add(new BasicNameValuePair("message",
"Hi, trying Android HTTP post!"));
// Url Encoding the POST parameters
try {
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePair));
} catch (UnsupportedEncodingException e) {
// writing error to Log
e.printStackTrace();
}
// Making HTTP Request
try {
HttpResponse response = httpClient.execute(httpPost);
// writing response to log
Log.d("Http Response:", response.toString());
} catch (ClientProtocolException e) {
// writing exception to log
e.printStackTrace();
} catch (IOException e) {
// writing exception to log
e.printStackTrace();
}
}
what is the implementation for the post method in the java restful web service , this is my code for the Rest sever what is wrong ?
#POST
#Path("{Login}")
#Consumes({"application/xml"})
public void Add(#PathParam("email") String email,AndroidClientLocation entity) {
entity.setEmail(email);
super.create(entity);
}

Multiple questions..
What are you using as container on server side
What is your base url mapping. Your API method's path being Login, how do are you routing the remaining part of the URL (/resources/rest.android.taxi.androidclientlocation) to the API.
The API consumes application/xml but the client code is not sending/setting Content-Type as application/xml, is it taken care by the client?
When you run the request from client what is the response (HTTP Error) that you get.
Where is your REST server running (Internal or External).
Answers to the question might clarify the request a bit more.

http://developer.android.com/tools/devices/emulator.html#networkaddresses
10.0.2.2 Special alias to your host loopback interface (i.e., 127.0.0.1 on your development machine)
http://localhost:8080/.
as per link & link2
Send a request to localhost' means to send it to the local machine. In your case that would be the Android device. You want to send the request to your desktop machine, which is a remote host. The problem is that the Appengine dev_sever by default only binds to the local address, so it can't be accessed remotely (i.e., from your Android device). You need to pass the --address option to make accessible from the outside. Check your computer's IP and pass it as the address. Something like:
dev_appserver.cmd --address=192.168.2.220

Problem with accessing google tasks with client login

I'm trying to write application for Android to access Google Tasks. I decided to use ClientLogin authorization method.
I'm getting ClientLogin "Auth" marker from first POST request. Then i try to retrieve a user's task lists with GET request. I wrote the following code for this:
String requestString = "https://www.googleapis.com/tasks/v1/users/#me/lists";
String resultString = "";
try {
URLConnection connection1 = null;
URL url = new URL(requestString);
connection1 = url.openConnection( );
HttpURLConnection httpsConnection1 = (HttpURLConnection)connection1;
httpsConnection1.setRequestMethod("GET");
httpsConnection1.setRequestProperty("Authorization", "GoogleLogin auth="+authkeyString);
httpsConnection1.setDoInput(true);
httpsConnection1.connect();
int responseCode = httpsConnection1.getResponseCode();
System.out.println(responseCode);
if (responseCode == HttpsURLConnection.HTTP_OK) {
InputStream in = httpsConnection1.getInputStream();
InputStreamReader isr = new InputStreamReader(in, "UTF-8");
StringBuffer data = new StringBuffer();
int c;
while ((c = isr.read()) != -1){
data.append((char) c);
}
resultString = new String (data.toString());
}
else{
resultString = "Errror - connection problem";
}
}
httpsConnection1.disconnect();
}
catch (MalformedURLException e) {
resultString = "MalformedURLException1:" + e.getMessage();
}
catch (IOException e) {
resultString = "IOException1:" + e.getMessage();
}
Here is "authkeyString" - string variable with authorization marker.
When i run application under real Android device i receive: "IOException:SSL handshake failure: Failure is ssl library, usually a protocol error ..... "
Also i tried to run this code from simple java application from desktop:
Exception in thread "main" java.lang.IllegalArgumentException: Illegal character(s) in message header value: GoogleLogin auth=DQ ..... UT
at sun.net.www.protocol.http.HttpURLConnection.checkMessageHeader(HttpURLConnection.java:428)
at sun.net.www.protocol.http.HttpURLConnection.isExternalMessageHeaderAllowed(HttpURLConnection.java:394)
at sun.net.www.protocol.http.HttpURLConnection.setRequestProperty(HttpURLConnection.java:2378)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.setRequestProperty(HttpsURLConnectionImpl.java:296)
at Tasks.main(Tasks.java:81)

ClientLogin with username / password
If you want to use ClientLogin with the Google APIs Client Library for Java , you'll need to setup a HttpRequestFactory that supports authentication.
private static HttpTransport transport = new ApacheHttpTransport();
public static HttpRequestFactory createRequestFactory(
final HttpTransport transport) {
return transport.createRequestFactory(new HttpRequestInitializer() {
public void initialize(HttpRequest request) {
GoogleHeaders headers = new GoogleHeaders();
headers.setApplicationName("MyApp/1.0");
request.headers=headers;
try {
authorizeTransport(request);
} catch (Exception e) {
e.printStackTrace();
}
}
});
Notice the authorizeTransport method, that will basically authorize the request. The authorizeTransport looks like this:
private void authorizeTransport(HttpRequest request) throws HttpResponseException, IOException {
// authenticate with ClientLogin
ClientLogin authenticator = new ClientLogin();
authenticator.authTokenType = Constants.AUTH_TOKEN_TYPE;
authenticator.username = Constants.USERNAME;
authenticator.password = Constants.PASSWORD;
authenticator.transport = transport;
try {
Response response = authenticator.authenticate();
request.headers.authorization=response.getAuthorizationHeaderValue();
} catch (HttpResponseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
You basically setup a ClientLogin authentication method by providing a username/passsword. The authenticate method will authenticate based on the provided values and returns a response object that can be added to the HTTP header to provide ClientLogin authentication.
Android AccountManager
In order to integrate with the Android AccountManager (avoiding the android user to type in his username / password) , you can find some sample code here http://code.google.com/p/google-api-java-client/wiki/AndroidAccountManager
The fact that the user doesn't need to key in his username/passwords adds to the users comfort level, but the solution remains relatively insecure.
I would strongly suggest doing the following :
Use a client library
I would suggest moving to Google APIs Client Library for Java for this type of interaction. It's Android compatible java client library for all kinds of Google APIs.
You don't want to be bothered with implementing low level HTTP, security and JSON plumbing.
The Google Task API Developers guide also mentions the same library. The library will take care of the authentication for you. If you want to use ClientLogin, all you'll have to do is specify a username/password, or integrate with the Android AccountManager.
Avoid using ClientLogin
ClientLogin is considered insecure, and a number of security holes have been found regarding this authentication mechanism. Google also doesn't recommend it. However, should you decide to continue using ClientLogin, the Google APIs Client Library for Java does support it.

Send GET HTTPS request but get 403 forbidden response, why?

Below is the URL I send to the WS after the handshake is done
"https://ekp.truefriend.com/COVIWeb/gate/AutoAuthentication.aspx?UserID=DP0001&BackUrl=http%3a%2f%2fgw.truefriendtest.com%2fCOVIWeb%2fApproval%2fForms%2fForm.aspx%3fmobileyn%3dY%26piid%3d96482621-6cc4-401c-a6f9-5ba6cb7ce26f%26wiid%3d425a9bc9-8607-4898-9158-ed9170da1d89%26fmpf%3dWF_A_DRAFT_PAPER01%26fmrv%3d0%26fiid%3d749526BE-B208-4987-B751-2DD0FC03F0F6%26fmid%3d24f6765d-69d1-429f-b0da-b540a064f0e2%26scid%3ddc4378f1-7edd-4d69-8fe4-5867ed32c8b9"
What it should do is redirecting the browser to BackUrl page given in the url. It display correct result in IE8 despite the certificate problem. In PC version of Chrome it display some code of the HTML. In Android, I get 403 Forbidden error.
HTTP/1.1 403 Forbidden ( The server denied the specified Uniform Resource Locator (URL). Contact the server administrator. )
I use this method to stream data
try{
URL url = new URL(urlString);
HttpsURLConnection.setDefaultHostnameVerifier(new FakeHostVerifier());
TrustManager[] trustAllCerts = new TrustManager[]{
new X509TrustManager() {
public java.security.cert.X509Certificate[] getAcceptedIssuers() {
Log.d("SSLDemo", "getAcceptedIssuers");
return null;
}
public void checkClientTrusted(
java.security.cert.X509Certificate[] certs, String authType) {
Log.d("SSLDemo", "Check Client Trusted");
}
public void checkServerTrusted(
java.security.cert.X509Certificate[] certs, String authType) {
Log.d("SSLDemo", "Check Server Trusted");
}
}
};
SSLContext sc = SSLContext.getInstance("TLS"); //"TLS"
sc.init(null, trustAllCerts, new java.security.SecureRandom());
HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
int port = 443;
SSLSocketFactory factory = HttpsURLConnection.getDefaultSSLSocketFactory();
socket = (SSLSocket)factory.createSocket(url.getHost(), port);
socket.startHandshake();
/**
* Connection Method
*/
String method = "GET";
String os = method + " "+urlString+" HTTP/1.0\r\n";
os += "Content-Length: 0";
os += "\r\n\r\n";
((SSLWeb)this.caller).updateRequest(urlString, method);
Log.i("TESTWEB", os);
BufferedWriter wout = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
wout.write(os);
wout.flush();
wout.close();
rd = new BufferedReader(new InputStreamReader(socket.getInputStream()));
//********* Not using thread
StringBuffer buff = new StringBuffer();
char[] buffer = new char[1024];
while(rd.read(buffer) > -1) {
buff.append(buffer);
Log.i("TESTWEB", "read buffer :" + String.valueOf(buffer));
}
Log.i("TESTWEB", "read line :" + buff.toString());
//**********
}catch(Exception e){
Log.e("TESTWEB", "Connecting error", e);
e.printStackTrace();
}
Is there something wrong with my code? I thought the problem was with the URL parameter, but it work in browser :(
I've been finding a way around the problem for the last three days now, no luck so far.
EDIT: This is FakeHostVerifier class that used to skip the certificate validation process. Isn't this correct?
public class FakeHostVerifier implements HostnameVerifier {
#Override
public boolean verify(String hostname, SSLSession session) {
return true;
}
}

As I was saying in a comment to another answer, this has nothing to do with trusting the server's certificate or not. If you get an HTTP response, even if it's a 403, that means that the HTTP connection was established, which also means that the underlying SSL/TLS connection was established. If your client doesn't trust the server certificate, the SSL/TLS connection will close before any HTTP traffic happens.
I'd try a few things:
Remove the Content-Length header. It's a GET request, so it doesn't have an entity. Implying a 0-length entity might confuse the server.
Try to set a User-Agent header to simulate the request as coming from a browser.
More generally, look at the headers a browser that work would send and try to reproduce them. (Try Accept header as well, that might be the cause of your problem with Chrome.)
EDIT: (other potential problem, more likely to be the cause)
If you urlstring variable really contains "https://ekp.truefriend.com/COVIWeb/gate/...", that's where the problem comes from.
When you send an HTTP GET the request should be like this:
GET /COVIWeb/gate/... HTTP/1.1
Host: ekp.truefriend.com
Not:
GET https://ekp.truefriend.com/COVIWeb/gate/... HTTP/1.1
(that's only for requests via a proxy, and doesn't apply to the HTTPS requests anyway.)
If you're using HTTP 1.0, you won't use the Host header, but it shouldn't really matter (unless that host serves multiple virtual hosts, which it can do, even over HTTPS). Consider using HTTP/1.1 if you can, although you may have to deal with closing the connection (content-length or chunked encoding perhaps).

Your question contains the answer. Upon trying to access the URL you specified in Chrome, you get a big red warning "The site's security certificate is not trusted!". While you can manually override in a browser and ignore the warning, your code treats this as a security problem and a dead end. It even recommends you contact the server administrator.
If you are the server's admin, change the SSL cert to a valid one. if not, ask the admin to do it. Failing that, try accessing the HTTP (non-SSL) version of the site.